How to Winterize a Sailboat: Rig, Sails, Engine, Plumbing and Storage

Walk the boat like a buyer would, as SpinSheet suggests: look for cracks, wear, corrosion, chafe and anything that broke this season. Note the jobs for the off-season and the spring. Take photos of hose routing, the engine and rigging details now; they help in March.

• Mast down is common where winters are windy or snowy. BoatUS points out that a tall rig adds a lot of windage to a boat on stands, and recommends unstepping the mast (plus extra jackstands) for deep-draft boats stored on trailers. With the mast down you can also inspect and service the masthead, sheaves, lights and fittings at ground level.
• Mast up saves crane fees and is allowed at many yards. If you leave it up, Jeanneau advises taking off and storing the running rigging and checking the standing rigging (chainplates, turnbuckles and attachment points), replacing anything worn.
• The hidden cost of leaving it up, according to Practical Sailor: it's easy to skip the close inspection, ice and salt residue can sit in the tops of the shroud terminals and speed corrosion, and chainplates take extra strain (and can start leaking) while a rigid boat holds a shaking spar. The hull can change shape a little in deep cold, so ask your rigger whether the standing rigging should be eased slightly for winter (not so loose that it slams back and forth). For a small trailer sailor with a deck-stepped mast, taking it down is the easy call, and in hurricane country unstepping improves the odds.
• Follow your yard's rules, and see the mast stepping and unstepping guide if it's coming down.

Discover Boating says to take all sails off and store them clean, dry and properly folded or rolled, including a roller-furling headsail. A furled jib left on all winter flogs in storms and keeps aging in the sun. Pick a calm day: SpinSheet calls sail removal one of the two days a year sailors want no wind. Look each sail over and decide whether it needs a sailmaker's cleaning, repair or storage. The sail care guide covers rinsing, drying and folding.

Remove sheets, control lines and (if the mast stays up and your yard permits) halyards. If you pull halyards out of the mast, tie in a thin messenger line first so you can pull them back through in spring. Soak lines in mild soapy water, rinse, dry completely and store them coiled indoors. Check for chafe, stiff spots and worn covers. If halyards stay rigged, tie them away from the mast so they don't slap all winter (SpinSheet notes neighbors and liveaboards appreciate it).

Jeanneau and Discover Boating both say to remove canvas, cushions, biminis, dodgers and anything that holds moisture, and store them somewhere dry so mildew doesn't take hold. Take electronics you can remove (handheld VHF, GPS, displays) home as well. Clean and dry canvas before storing it; see the canvas and vinyl care guide.

Discover Boating's list includes checking blocks, winches and cleats. While you're at it, look for cracked gelcoat around fittings (a sign of a leak path to the core), chainplate stains below deck, and bent or missing cotter pins. If a winch hasn't been serviced in years, winter is a good time to do it in the shop.

Most auxiliary diesels need fresh oil, filters, treated fuel, antifreeze through the raw-water side and the impeller out. Follow the diesel inboard winterizing guide for the full routine, which is built on Westerbeke's published lay-up checklist. On the hard, Westerbeke says to disconnect the propeller shaft coupling and check engine alignment in spring once the boat is back in the water, the mast is stepped and the rigging is tuned. Small sailboats with an outboard follow the outboard winterizing guide instead.

Haul-out is the time to check the saildrive leg's oil for a milky color, look over the rubber hull seal (diaphragm) and replace the drive's anode if needed. See the saildrive care guide and follow your drive maker's lay-up and seal-replacement schedule. Milky oil or a damaged seal is a job for a pro.

Drain or antifreeze every line, the pump and the water heater, as the freshwater winterizing guide explains. Discover Boating says to run antifreeze through each fixture until the pink color comes out the other end, and to remove and label any drain plugs for spring. Jeanneau adds cleaning the head and plumbing and emptying the tanks so nothing freezes. Pump out the holding tank, rinse it, and protect the head and its hoses as the marine head guide shows. Don't forget the shower sump, deck washdown and any watermaker (follow its maker's "pickling" steps).

Charge the batteries fully and turn off the battery switches (Jeanneau). Westerbeke's rule is that batteries left aboard must stay fully charged so they can't freeze; otherwise take them home. A small solar panel or a monitored charger can keep them topped up, as SpinSheet's crew does. See the marine battery guide.

Moisture is the cabin's biggest winter enemy, says Discover Boating. Take cushions, bedding, paper goods, food and liquids (soaps, sunscreen, cleaners) off the boat. Jeanneau suggests cleaning lockers and leaving them, plus doors and the fridge, open so air can move. Wedge the icebox open. Moisture absorbers help in a closed boat; use a dehumidifier only with safe, inspected shore power.

BoatUS says a cradle built for your model gives the best support; a cradle built for a different boat doesn't. On jackstands, its storage article calls for at least three stands per side on boats over 26 feet, set wide, chained together and resting on plywood, with the weight on the keel sitting on wide timbers (never cinder blocks). Sight along the hull after blocking and again about two weeks later. Some builders have special keel-support instructions, so check your manual. BoatUS suggests a written blocking plan (from the builder, or sketched with the yard manager) showing where stands and blocks go; keep it and hand a copy to whoever hauls the boat next time. In windy spots, straps from strong points on the boat to ground anchors add a lot of protection. Empty the water tanks before haul-out to take weight off the hull, but don't run the fuel tank low (condensation). The boat stands and blocking guide has the details.

Check the rudder and drain holes. If the rudder is still dripping a few days after haul-out, BoatUS says water is trapped inside and can freeze and split the laminate. Getting it out may mean drilling a small drain hole at the bottom of the leading edge; ask the yard or a fiberglass pro, then find where the water got in before spring. Also clear the little drain holes in stanchion bases, the mast step and cockpit lockers, and open the drain plugs on seacocks that have them so no trapped water freezes.

A fitted cover, frame and tarp, or shrink wrap all work if they shed snow and water and are vented. SpinSheet notes vented covers are what keep mildew away. BoatUS warns: never tie the cover or tarp to the jackstands, because wind loads on the cover can pull the stands out. Leave cockpit scuppers and drains open so water can escape. Build a real frame: BoatUS has seen snow and ice loads on a cover drive a stanchion straight through a deck, and tarps tied in a web of lines often shred in the first storm and dump snow into the boat. Its claims files also show shrink wrap fires every fall, so shrink wrapping is best left to a pro. See the shrink wrap and boat cover guides.

If the boat stays in, keep the engine raw-water side, plumbing and head protected exactly as above, close all seacocks you don't need (the cockpit drains usually stay open), keep the bilge pump powered and batteries charged, and check dock lines and chafe gear. In ice country, a bubbler or de-icer is essential; see the in-water winter storage guide. SpinSheet stresses visiting often, especially during storms, and confirming whether the marina checks lines and bilges.

Write down the date, engine hours, fluids used, what's been removed (sails, halyards, impeller, plugs) and where each item is stored. Tag the ignition and the companionway with your "remove before start" list. The sailboat spring commissioning guide picks up from that list.